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/*

 *  (c) Copyright 1986 HEWLETT-PACKARD COMPANY

 *

 *  To anyone who acknowledges that this file is provided "AS IS"

 *  without any express or implied warranty:

 *      permission to use, copy, modify, and distribute this file

 *  for any purpose is hereby granted without fee, provided that

 *  the above copyright notice and this notice appears in all

 *  copies, and that the name of Hewlett-Packard Company not be

 *  used in advertising or publicity pertaining to distribution

 *  of the software without specific, written prior permission.

 *  Hewlett-Packard Company makes no representations about the

 *  suitability of this software for any purpose.

 */

/* SPECTRUM_ID: @(#)memchr.s    37.4     86/04/23 */

/*

 * memchr(s, c, n)

 *

 * returns pointer to first occurrence of char c

 * in first n characters of memory area s,

 * or null if c does not occur.

 */

#include "DEFS.h"

#define FROM    arg0

#define CHAR    arg1

#define COUNT   arg2

#define TEMP1   r19

ENTRY(memchr)

        comb,<= COUNT,r0,memchrexit     /* return if count is zero */

        copy    r0,ret0                 /* null if c not found in n chars */

        depi    0,23,24,CHAR            /* make char unsigned */

        ldbs,ma 1(FROM),TEMP1

memchrloop:

        comb,=,n        TEMP1,CHAR,memchrequal

        addib,<>        -1,COUNT,memchrloop

        ldbs,ma 1(FROM),TEMP1

        b,n     memchrexit

memchrequal:

        ldo     -1(FROM),ret0

memchrexit:

EXIT(memchr)